Accessing Metadata Storage Trees in a Storage Network

ABSTRACT

A method includes error encoding data to produce a plurality of data slices. Metadata is determined for a data slice of the plurality of data slices. The metadata is stored in a metadata storage tree. The data slice is stored in a slice storage location indicated by the metadata. Based on determining to access the data slice, the metadata for the data slice is accessed in the metadata storage tree to determine the slice storage location for the data slice, and the data slice is accessed in the slice storage location based on determining the slice storage location for the data slice via accessing the metadata storage tree.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present U.S. Utility Patent Application claims priority pursuant to 35 U.S.C. § 120 as a continuation of U.S. Utility application Ser. No. 17/834,254, entitled “Utilizing Metadata Storage Trees in a Vast Storage Network”, filed Jun. 7, 2022, which is a continuation-in-part of U.S. Utility application Ser. No. 15/397,374, entitled “ALLOCATING CACHE MEMORY IN A DISPERSED STORAGE NETWORK”, filed Jan. 3, 2017, issued as U.S. Pat. No. 11,582,299 on Feb. 14, 2023, which claims priority pursuant to 35 U.S.C. § 119(e) to U.S. Provisional Application No. 62/287,145, entitled “VERIFYING INTEGRITY OF ENCODED DATA SLICES”, filed Jan. 26, 2016, all of which are hereby incorporated herein by reference in their entirety and made part of the present U.S. Utility Patent Application for all purposes.

U.S. Utility application Ser. No. 17/834,254 also claims priority pursuant to 35 U.S.C. § 120, as a continuation-in-part of U.S. Utility patent application Ser. No. 17/655,841, entitled “Selecting Storage Resources Based on Estimated Performance” filed Mar. 22, 2022, which claims priority pursuant to 35 U.S.C. § 120, as a continuation-in-part of U.S. Utility patent application Ser. No. 17/066,873, entitled “OPTIMIZED SELECTION OF PARTICIPANTS IN DISTRIBUTED DATA REBUILD/VERIFICATION” filed Oct. 9, 2020, issued as U.S. Pat. No. 11,307,930 on Apr. 19, 2022, which claims priority pursuant to 35 U.S.C. § 120, as a continuation-in-part of U.S. Utility patent application Ser. No. 16/136,362, entitled “REMOTE STORAGE VERIFICATION,” filed Sep. 20, 2018, issued as U.S. Pat. No. 10,802,763 on Oct. 13, 2020, which is a continuation-in-part of U.S. Utility patent application Ser. No. 15/285,582, entitled “SHARED OWNERSHIP OF NAMESPACE RANGES,” filed Oct. 5, 2016, issued as U.S. Pat. No. 10,372,350 on Aug. 6, 2019, which claims priority a continuation-in-part of U.S. Utility patent application Ser. No. 13/291,030, entitled “PARTITIONING DATA FOR STORAGE IN A DISPERSED STORAGE NETWORK,” filed Nov. 7, 2011, issued as U.S. Pat. No. 9,483,398 on Nov. 1, 2016, which claims priority pursuant to 35 U.S.C. § 119(e) to U.S. Provisional Application No. 61/417,873, entitled “DATA REBUILDING IN A DISPERSED STORAGE NETWORK,” filed Nov. 29, 2010, all of which are hereby incorporated herein by reference in their entirety and made part of the present U.S. Utility Patent Application for all purposes.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC

Not applicable.

BACKGROUND OF THE INVENTION Technical Field of the Invention

This invention relates generally to computer networks and more particularly to dispersing error encoded data.

Description of Related Art

Computing devices are known to communicate data, process data, and/or store data. Such computing devices range from wireless smart phones, laptops, tablets, personal computers (PC), work stations, and video game devices, to data centers that support millions of web searches, stock trades, or on-line purchases every day. In general, a computing device includes a central processing unit (CPU), a memory system, user input/output interfaces, peripheral device interfaces, and an interconnecting bus structure.

As is further known, a computer may effectively extend its CPU by using “cloud computing” to perform one or more computing functions (e.g., a service, an application, an algorithm, an arithmetic logic function, etc.) on behalf of the computer. Further, for large services, applications, and/or functions, cloud computing may be performed by multiple cloud computing resources in a distributed manner to improve the response time for completion of the service, application, and/or function. For example, Hadoop is an open source software framework that supports distributed applications enabling application execution by thousands of computers.

In addition to cloud computing, a computer may use “cloud storage” as part of its memory system. As is known, cloud storage enables a user, via its computer, to store files, applications, etc. on an Internet storage system. The Internet storage system may include a RAID (redundant array of independent disks) system and/or a dispersed storage system that uses an error correction scheme to encode data for storage.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

FIG. 1 is a schematic block diagram of an embodiment of a dispersed or distributed storage network (DSN) in accordance with various examples;

FIG. 2 is a schematic block diagram of an embodiment of a computing core in accordance with various examples;

FIG. 3 is a schematic block diagram of an example of dispersed storage error encoding of data in accordance with various examples;

FIG. 4 is a schematic block diagram of a generic example of an error encoding function in accordance with various examples;

FIG. 5 is a schematic block diagram of a specific example of an error encoding function in accordance with various examples;

FIG. 6 is a schematic block diagram of an example of a slice name of an encoded data slice (EDS) in accordance with various examples;

FIG. 7 is a schematic block diagram of an example of dispersed storage error decoding of data in accordance with various examples;

FIG. 8 is a schematic block diagram of a generic example of an error decoding function in accordance with various examples;

FIG. 9 is a schematic block diagram of an embodiment of a dispersed or distributed storage network (DSN) in accordance with various examples; and

FIG. 10 is a logic diagram of an example of a method of allocating cache memory in accordance with various examples.

FIG. 11 is a schematic block diagram of an embodiment of a dispersed or distributed storage network (DSN) in accordance with various examples;

FIG. 12 is a logic diagram of an example of a method of utilizing tree storage structures in accordance with various examples; and

FIG. 13 is a logic diagram of an example of a method of utilizing a metadata storage tree in accordance with various examples.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a schematic block diagram of an embodiment of a dispersed, or distributed, storage network (DSN) 10 that includes a plurality of computing devices 12-16, a managing unit 18, an integrity processing unit 20, and a DSN memory 22. The components of the DSN 10 are coupled to a network 24, which may include one or more wireless and/or wire lined communication systems; one or more non-public intranet systems and/or public internet systems; and/or one or more local area networks (LAN) and/or wide area networks (WAN).

The DSN memory 22 includes a plurality of storage units 36 that may be located at geographically different sites (e.g., one in Chicago, one in Milwaukee, etc.), at a common site, or a combination thereof. For example, if the DSN memory 22 includes eight storage units 36, each storage unit is located at a different site. As another example, if the DSN memory 22 includes eight storage units 36, all eight storage units are located at the same site. As yet another example, if the DSN memory 22 includes eight storage units 36, a first pair of storage units are at a first common site, a second pair of storage units are at a second common site, a third pair of storage units are at a third common site, and a fourth pair of storage units are at a fourth common site. Note that a DSN memory 22 may include more or less than eight storage units 36. Further note that each storage unit 36 includes a computing core (as shown in FIG. 2 , or components thereof) and a plurality of memory devices for storing dispersed error encoded data.

In various embodiments, each of the storage units operates as a distributed storage and task (DST) execution unit, and is operable to store dispersed error encoded data and/or to execute, in a distributed manner, one or more tasks on data. The tasks may be a simple function (e.g., a mathematical function, a logic function, an identify function, a find function, a search engine function, a replace function, etc.), a complex function (e.g., compression, human and/or computer language translation, text-to-voice conversion, voice-to-text conversion, etc.), multiple simple and/or complex functions, one or more algorithms, one or more applications, etc. Hereafter, a storage unit may be interchangeably referred to as a dispersed storage and task (DST) execution unit and a set of storage units may be interchangeably referred to as a set of DST execution units.

Each of the computing devices 12-16, the managing unit 18, and the integrity processing unit 20 include a computing core 26, which includes network interfaces 30-33. Computing devices 12-16 may each be a portable computing device and/or a fixed computing device. A portable computing device may be a social networking device, a gaming device, a cell phone, a smart phone, a digital assistant, a digital music player, a digital video player, a laptop computer, a handheld computer, a tablet, a video game controller, and/or any other portable device that includes a computing core. A fixed computing device may be a computer (PC), a computer server, a cable set-top box, a satellite receiver, a television set, a printer, a fax machine, home entertainment equipment, a video game console, and/or any type of home or office computing equipment. Note that each managing unit 18 and the integrity processing unit 20 may be separate computing devices, may be a common computing device, and/or may be integrated into one or more of the computing devices 12-16 and/or into one or more of the storage units 36. In various embodiments, computing devices 12-16 can include user devices and/or can be utilized by a requesting entity generating access requests, which can include requests to read or write data to storage units in the DSN.

Each interface 30, 32, and 33 includes software and hardware to support one or more communication links via the network 24 indirectly and/or directly. For example, interface 30 supports a communication link (e.g., wired, wireless, direct, via a LAN, via the network 24, etc.) between computing devices 14 and 16. As another example, interface 32 supports communication links (e.g., a wired connection, a wireless connection, a LAN connection, and/or any other type of connection to/from the network 24) between computing devices 12 & 16 and the DSN memory 22. As yet another example, interface 33 supports a communication link for each of the managing unit 18 and the integrity processing unit 20 to the network 24.

Computing devices 12 and 16 include a dispersed storage (DS) client module 34, which enables the computing device to dispersed storage error encode and decode data as subsequently described with reference to one or more of FIGS. 3-8 . In this example embodiment, computing device 16 functions as a dispersed storage processing agent for computing device 14. In this role, computing device 16 dispersed storage error encodes and decodes data on behalf of computing device 14. With the use of dispersed storage error encoding and decoding, the DSN 10 is tolerant of a significant number of storage unit failures (the number of failures is based on parameters of the dispersed storage error encoding function) without loss of data and without the need for a redundant or backup copies of the data. Further, the DSN 10 stores data for an indefinite period of time without data loss and in a secure manner (e.g., the system is very resistant to unauthorized attempts at accessing the data).

In operation, the managing unit 18 performs DS management services. For example, the managing unit 18 establishes distributed data storage parameters (e.g., vault creation, distributed storage parameters, security parameters, billing information, user profile information, etc.) for computing devices 12-14 individually or as part of a group of user devices. As a specific example, the managing unit 18 coordinates creation of a vault (e.g., a virtual memory block associated with a portion of an overall namespace of the DSN) within the DSN memory 22 for a user device, a group of devices, or for public access and establishes per vault dispersed storage (DS) error encoding parameters for a vault. The managing unit 18 facilitates storage of DS error encoding parameters for each vault by updating registry information of the DSN 10, where the registry information may be stored in the DSN memory 22, a computing device 12-16, the managing unit 18, and/or the integrity processing unit 20.

The DSN managing unit 18 creates and stores user profile information (e.g., an access control list (ACL)) in local memory and/or within memory of the DSN memory 22. The user profile information includes authentication information, permissions, and/or the security parameters. The security parameters may include encryption/decryption scheme, one or more encryption keys, key generation scheme, and/or data encoding/decoding scheme.

The DSN managing unit 18 creates billing information for a particular user, a user group, a vault access, public vault access, etc. For instance, the DSN managing unit 18 tracks the number of times a user accesses a non-public vault and/or public vaults, which can be used to generate a per-access billing information. In another instance, the DSN managing unit 18 tracks the amount of data stored and/or retrieved by a user device and/or a user group, which can be used to generate a per-data-amount billing information.

As another example, the managing unit 18 performs network operations, network administration, and/or network maintenance. Network operations includes authenticating user data allocation requests (e.g., read and/or write requests), managing creation of vaults, establishing authentication credentials for user devices, adding/deleting components (e.g., user devices, storage units, and/or computing devices with a DS client module 34) to/from the DSN 10, and/or establishing authentication credentials for the storage units 36. Network administration includes monitoring devices and/or units for failures, maintaining vault information, determining device and/or unit activation status, determining device and/or unit loading, and/or determining any other system level operation that affects the performance level of the DSN 10. Network maintenance includes facilitating replacing, upgrading, repairing, and/or expanding a device and/or unit of the DSN 10.

The integrity processing unit 20 performs rebuilding of ‘bad’ or missing encoded data slices. At a high level, the integrity processing unit 20 performs rebuilding by periodically attempting to retrieve/list encoded data slices, and/or slice names of the encoded data slices, from the DSN memory 22. For retrieved encoded slices, they are checked for errors due to data corruption, outdated version, etc. If a slice includes an error, it is flagged as a ‘bad’ slice. For encoded data slices that were not received and/or not listed, they are flagged as missing slices. Bad and/or missing slices are subsequently rebuilt using other retrieved encoded data slices that are deemed to be good slices to produce rebuilt slices. The rebuilt slices are stored in the DSN memory 22.

FIG. 2 is a schematic block diagram of an embodiment of a computing core 26 that includes a processing module 50, a memory controller 52, main memory 54, a video graphics processing unit 55, an input/output (IO) controller 56, a peripheral component interconnect (PCI) interface 58, an IO interface module 60, at least one IO device interface module 62, a read only memory (ROM) basic input output system (BIOS) 64, and one or more memory interface modules. The one or more memory interface module(s) includes one or more of a universal serial bus (USB) interface module 66, a host bus adapter (HBA) interface module 68, a network interface module 70, a flash interface module 72, a hard drive interface module 74, and a DSN interface module 76.

The DSN interface module 76 functions to mimic a conventional operating system (OS) file system interface (e.g., network file system (NFS), flash file system (FFS), disk file system (DFS), file transfer protocol (FTP), web-based distributed authoring and versioning (WebDAV), etc.) and/or a block memory interface (e.g., small computer system interface (SCSI), internet small computer system interface (iSCSI), etc.). The DSN interface module 76 and/or the network interface module 70 may function as one or more of the interface 30-33 of FIG. 1 . Note that the IO device interface module 62 and/or the memory interface modules 66-76 may be collectively or individually referred to as IO ports.

FIG. 3 is a schematic block diagram of an example of dispersed storage error encoding of data. When a computing device 12 or 16 has data to store it disperse storage error encodes the data in accordance with a dispersed storage error encoding process based on dispersed storage error encoding parameters. Here, the computing device stores data object 40, which can include a file (e.g., text, video, audio, etc.), or other data arrangement. The dispersed storage error encoding parameters include an encoding function (e.g., information dispersal algorithm (IDA), Reed-Solomon, Cauchy Reed-Solomon, systematic encoding, non-systematic encoding, on-line codes, etc.), a data segmenting protocol (e.g., data segment size, fixed, variable, etc.), and per data segment encoding values. The per data segment encoding values include a total, or pillar width, number (T) of encoded data slices per encoding of a data segment i.e., in a set of encoded data slices); a decode threshold number (D) of encoded data slices of a set of encoded data slices that are needed to recover the data segment; a read threshold number (R) of encoded data slices to indicate a number of encoded data slices per set to be read from storage for decoding of the data segment; and/or a write threshold number (W) to indicate a number of encoded data slices per set that must be accurately stored before the encoded data segment is deemed to have been properly stored. The dispersed storage error encoding parameters may further include slicing information (e.g., the number of encoded data slices that will be created for each data segment) and/or slice security information (e.g., per encoded data slice encryption, compression, integrity checksum, etc.).

In the present example, Cauchy Reed-Solomon has been selected as the encoding function (a generic example is shown in FIG. 4 and a specific example is shown in FIG. 5 ); the data segmenting protocol is to divide the data object into fixed sized data segments; and the per data segment encoding values include: a pillar width of 5, a decode threshold of 3, a read threshold of 4, and a write threshold of 4. In accordance with the data segmenting protocol, the computing device 12 or 16 divides data object 40 into a plurality of fixed sized data segments (e.g., 1 through Y of a fixed size in range of Kilo-bytes to Tera-bytes or more). The number of data segments created is dependent of the size of the data and the data segmenting protocol.

The computing device 12 or 16 then disperse storage error encodes a data segment using the selected encoding function (e.g., Cauchy Reed-Solomon) to produce a set of encoded data slices. FIG. 4 illustrates a generic Cauchy Reed-Solomon encoding function, which includes an encoding matrix (EM), a data matrix (DM), and a coded matrix (CM). The size of the encoding matrix (EM) is dependent on the pillar width number (T) and the decode threshold number (D) of selected per data segment encoding values. To produce the data matrix (DM), the data segment is divided into a plurality of data blocks and the data blocks are arranged into D number of rows with Z data blocks per row. Note that Z is a function of the number of data blocks created from the data segment and the decode threshold number (D). The coded matrix is produced by matrix multiplying the data matrix by the encoding matrix.

FIG. 5 illustrates a specific example of Cauchy Reed-Solomon encoding with a pillar number (T) of five and decode threshold number of three. In this example, a first data segment is divided into twelve data blocks (D1-D12). The coded matrix includes five rows of coded data blocks, where the first row of X11-X14 corresponds to a first encoded data slice (EDS 1_1), the second row of X21-X24 corresponds to a second encoded data slice (EDS 2_1), the third row of X31-X34 corresponds to a third encoded data slice (EDS 3_1), the fourth row of X41-X44 corresponds to a fourth encoded data slice (EDS 4_1), and the fifth row of X51-X54 corresponds to a fifth encoded data slice (EDS 5_1). Note that the second number of the EDS designation corresponds to the data segment number.

Returning to the discussion of FIG. 3 , the computing device also creates a slice name (SN) for each encoded data slice (EDS) in the set of encoded data slices. A typical format for a slice name 80 is shown in FIG. 6 . As shown, the slice name (SN) 80 includes a pillar number of the encoded data slice (e.g., one of 1-T), a data segment number (e.g., one of 1-Y), a vault identifier (ID), a data object identifier (ID), and may further include revision level information of the encoded data slices. The slice name functions as, at least part of, a DSN address for the encoded data slice for storage and retrieval from the DSN memory 22.

As a result of encoding, the computing device 12 or 16 produces a plurality of sets of encoded data slices, which are provided with their respective slice names to the storage units for storage. As shown, the first set of encoded data slices includes EDS 1_1 through EDS 5_1 and the first set of slice names includes SN 1_1 through SN 5_1 and the last set of encoded data slices includes EDS 1_Y through EDS 5_Y and the last set of slice names includes SN 1_Y through SN 5_Y.

FIG. 7 is a schematic block diagram of an example of dispersed storage error decoding of a data object that was dispersed storage error encoded and stored in the example of FIG. 4 . In this example, the computing device 12 or 16 retrieves from the storage units at least the decode threshold number of encoded data slices per data segment. As a specific example, the computing device retrieves a read threshold number of encoded data slices.

To recover a data segment from a decode threshold number of encoded data slices, the computing device uses a decoding function as shown in FIG. 8 . As shown, the decoding function is essentially an inverse of the encoding function of FIG. 4 . The coded matrix includes a decode threshold number of rows (e.g., three in this example) and the decoding matrix in an inversion of the encoding matrix that includes the corresponding rows of the coded matrix. For example, if the coded matrix includes rows 1, 2, and 4, the encoding matrix is reduced to rows 1, 2, and 4, and then inverted to produce the decoding matrix.

FIG. 9 is a schematic block diagram of another embodiment of a dispersed storage network (DSN) that includes a plurality of user devices 1-U, the network 24, a plurality of distributed storage and task (DST) processing units 1-D, the managing unit 18 of FIG. 1 , and a set of storage units 1-n. Each user device may be implemented utilizing at least one of the computing device 12 and the computing device 14 of FIG. 1 . Each DST processing unit may be implemented utilizing the computing device 16 of FIG. 1 , for example, functioning as a dispersed storage processing agent for computing device 14 as described previously. Each DST processing unit includes a corresponding cache memory. The cache memory may be implemented utilizing the computing core 26 of FIG. 2 . Each storage unit may be implemented utilizing storage unit 36 of FIG. 1 . The DSN functions to allocate the cache memory, where the cache memory is utilized by at least one of the plurality of DST processing units and/or the set of storage units for temporary storage of data objects and/or encoded data slices, where the user devices perform, via the network 24, data access with the DST processing units, and where the DST processing units perform, via the network 24, encoded data slice access with the set of storage units.

In an example of operation of the allocating of the cache memory, the managing unit 18 obtains access information from the plurality of DST processing units and/or the set of storage units, where each DST processing unit generates access information to include one or more of a data name, a data type, a user device identifier, a data size indicator, a data access frequency level indicator, a data access time, a cache memory utilization level, and a cache miss rate level (e.g., a number of instances where cache utilization would be beneficial but was not available per unit of time). The obtaining includes at least one of issuing a query, interpreting a query response, and receiving the access information.

Having obtained the access information, the managing unit 18 calculates cache memory utilization information based on the access information. The calculating includes interpreting the access information to produce one or more of a frequency of data access, efficiency of cache memory utilization, a frequency of non-cache memory utilization, a data aging rate (e.g., how long the data has persisted), a data cooling rate (e.g., a rate of a drop-off of access frequency), and access rate by datatype, and an access rate by user identifier.

Having calculated the cache memory utilization information, the managing unit 18 issues configuration information based on the cache memory utilization information. The issuing includes updating one or more of a cache memory size, a cache time by slice name, a cache time by data name, a cache memory allocation level, etc., and sending, via the network 24, the configuration information to one or more DST processing units and/or one or more storage units to facilitate configuration of cache memory associated with the one or more DST processing units and the one or more storage units.

In various embodiments, a processing system of a dispersed storage network (DSN) managing unit includes at least one processor and a memory that stores operational instructions, that when executed by the at least one processor cause the processing system to receive access information from a plurality of DST processing units via a network. Cache memory utilization data is generated based on the access information. Configuration instructions are generated for transmission via the network to the plurality of DST processing units based on the cache memory utilization data.

In various embodiments, the access information includes a data name, a data type, a user device identifier, a data size indicator, a data access frequency level indicator, and/or a data access time. In various embodiments, the access information includes a cache memory utilization level and/or a cache miss rate level. In various embodiments, a plurality of access information requests are generated for transmission via the network to the plurality of DST processing units, and the access information is received in response to the plurality of access information requests.

In various embodiments, generating the cache memory utilization data includes calculating frequency of data access, efficiency of cache memory utilization and/or frequency of non-cache memory utilization. In various embodiments, generating the cache memory utilization data includes calculating an aging rate, a data cooling rate, access rate by datatype, and/or access rate by user identifier. In various embodiments, the configuration instructions include a request to update at least one of: cache memory size, cache time by slice name, cache time by data name, or a cache memory allocation level.

In various embodiments, additional access information is received from a plurality of storage units via the network. Generating the cache memory utilization data is further based on the additional access information, and the configuration instructions are further transmitted to the plurality of storage units. In various embodiments, at least one cache memory is utilized by at least one of the plurality of DST processing units for temporary storage of data objects and/or encoded data slices, and the cache memory utilization data is based on utilization of the at least one cache memory.

FIG. 10 is a flowchart illustrating an example of allocating cache memory. In particular, a method is presented for use in association with one or more functions and features described in conjunction with FIGS. 1-9 , for execution by a dispersed storage network (DSN) managing unit that includes a processor or via another processing system of a dispersed storage network that includes at least one processor and memory that stores instruction that configure the processor or processors to perform the steps described below. Step 1002 includes obtaining access information from a plurality of DST processing units. Step 1004 includes calculating cache memory utilization information based on the access information. Step 1006 includes issuing configuration information to the plurality of DST processing units based on the cache memory utilization information.

In various embodiments, the access information includes a data name, a data type, a user device identifier, a data size indicator, a data access frequency level indicator, and/or a data access time. In various embodiments, the access information includes a cache memory utilization level and/or a cache miss rate level. In various embodiments, a plurality of access information requests are generated for transmission via the network to the plurality of DST processing units, and the access information is received in response to the plurality of access information requests.

In various embodiments, calculating the cache memory utilization information includes calculating frequency of data access, efficiency of cache memory utilization and/or frequency of non-cache memory utilization. In various embodiments, calculating the cache memory utilization information includes calculating an aging rate, a data cooling rate, access rate by datatype, and/or access rate by user identifier. In various embodiments, the configuration information includes a request to update at least one of: cache memory size, cache time by slice name, cache time by data name, or a cache memory allocation level.

In various embodiments, additional access information is received from a plurality of storage units via the network. calculating the cache memory utilization information is further based on the additional access information, and the configuration information is further transmitted to the plurality of storage units. In various embodiments, at least one cache memory is utilized by at least one of the plurality of DST processing units for temporary storage of data objects and/or encoded data slices, and the cache memory utilization information is based on utilization of the at least one cache memory.

In various embodiments, a non-transitory computer readable storage medium includes at least one memory section that stores operational instructions that, when executed by a processing system of a dispersed storage network (DSN) that includes a processor and a memory, causes the processing system to receive access information from a plurality of DST processing units via a network. Cache memory utilization data is generated based on the access information. Configuration instructions are generated for transmission via the network to the plurality of DST processing units based on the cache memory utilization data.

FIG. 11 is a schematic block diagram of another embodiment of a dispersed storage network (DSN) that includes a distributed storage and task (DST) processing unit 916, the network 24 of FIG. 1 , and a set of DST execution units 1-n. The DST processing unit can be implemented by utilizing the computing device 16 of FIG. 1 , for example, functioning as a dispersed storage processing agent for computing device 14 as described previously. Each DST execution unit can be implemented by utilizing the storage unit 36 of FIG. 1 , for example, operable to store dispersed error encoded data and/or to execute, in a distributed manner, one or more tasks on data as described previously. Each DST execution unit can include a processing module 84, a solid-state memory 986, and a magnetic drive memory 988, which can be implemented, for example, by utilizing the computing core of FIG. 2 . The DSN functions to store slice metadata and encoded data slices.

In an example of operation of the storing of the slice metadata and the encoded data slices, when initializing utilization of the storage unit, the processing module 84 can establish a storage tree structure within one or more memories, where the one or more memories includes at least two memory types (e.g., the solid-state memory 986 and the magnetic drive memory 988), where a top of the tree structure includes storage trees to store slice metadata and a bottom of the tree structure includes storage trees to store encoded data slices associated with the slice metadata. Establishing the storage tree structure can include identifying available memory types, generating tree structures, and/or storing tree structures within the memory types.

Having established the storage tree structure, when receiving a slice access transmission that includes a write slice request, the processing module 84 can utilize the tree structure to accommodate storage of one or more encoded data slices of the write slice request in accordance with a tree utilization approach. Tree utilization can includes extracting slice metadata from the message, storing a slice metadata in a storage tree associated with a higher performance memory (e.g., the solid-state memory 986) when the tree utilization approach includes storing metadata in the higher performance memory, and/or storing the encoded data slices at a location associated with the slice metadata in a tree structure that is associated with the lower performance memory when the tree utilization approach includes storing encoded data slices in the lower performance memory (e.g., in the magnetic drive memory 988).

When utilization of a tree within the tree structure compares unfavorably to a tree utilization threshold level (e.g., exceeds the threshold level and/or too many entries beyond the capability of a physical memory), the processing module 84 can expand the tree structure to accommodate further storage capability. For example, the processing module 84 adds another tree to the tree structure and associates the other tree with a best available memory type.

In various embodiments, a processing system of a dispersed storage and task (DST) execution unit includes at least one processor and a memory that stores operational instructions, that when executed by the at least one processor cause the processing system to receive a slice write request via a network that includes a data slice and extract metadata from the data slice. The metadata is stored in a metadata storage tree in a first memory device of the DST execution unit and the data slice is stored in a slice storage tree in a second memory device of the DST execution unit based on tree utilization parameters.

In various embodiments, the first memory device has a higher performance level than the second memory device based on the tree utilization parameters indicating that metadata is stored in higher performance memory than data slices. In various embodiments, the first memory device has a lower performance level than the second memory device based on the tree utilization parameters indicating that metadata is stored in lower performance memory than data slices. In various embodiments, the first memory device includes solid-state memory, and wherein the second memory device includes magnetic drive memory. In various embodiments, metadata entries of the metadata storage tree include a tree address corresponding to a location of the corresponding data slice in the slice storage tree.

In various embodiments, the tree utilization parameters are generated by selecting the first memory device to store the metadata storage tree and selecting the second memory device to store the slice storage tree. An initial metadata storage tree structure is generated in the first memory and an initial slice storage tree structure is generated in the second memory. In various embodiments, generating the tree utilization parameters further includes selecting a first plurality of memory devices to store a plurality of metadata storage trees and selecting a second plurality of memory devices to store a plurality of slice storage trees. In various embodiments, the first memory device is selected from the first plurality of memory devices to store the extracted metadata and the second memory device is selected from the second plurality of memory devices to store the received data slice based on the tree utilization parameters.

In various embodiments, a tree utilization threshold is compared to a metadata tree utilization level associated with the metadata storage tree and/or a slice tree utilization level associated with the slice storage tree. The tree utilization parameters are updated by selecting a third memory device to store a third storage tree when tree utilization threshold compares unfavorably to the metadata tree utilization level and/or the slice tree utilization level. In various embodiments, the third memory device includes a highest performing memory type, and the third memory device is selected based on the highest performing memory type.

FIG. 12 is a flowchart illustrating an example of utilizing tree storage structures. In particular, a method is presented for use in association with one or more functions and features described in conjunction with some or all of FIGS. 1-11 for execution by a dispersed storage and task (DST) execution unit that includes a processor or via another processing system of a dispersed storage network that includes at least one processor and memory that stores instruction that configure the processor or processors to perform the steps described below. Step 1082 includes receiving a slice write request via a network that includes a data slice. Step 1084 includes extracting metadata from the data slice. Step 1086 includes storing the metadata in a metadata storage tree in a first memory device of the DST execution unit and storing the data slice in a slice storage tree in a second memory device of the DST execution unit based on tree utilization parameters.

In various embodiments, the first memory device has a higher performance level than the second memory device based on the tree utilization parameters indicating that metadata is stored in higher performance memory than data slices. In various embodiments, the first memory device has a lower performance level than the second memory device based on the tree utilization parameters indicating that metadata is stored in lower performance memory than data slices. In various embodiments, the first memory device includes solid-state memory, and wherein the second memory device includes magnetic drive memory. In various embodiments, metadata entries of the metadata storage tree include a tree address corresponding to a location of the corresponding data slice in the slice storage tree.

In various embodiments, the tree utilization parameters are generated by selecting the first memory device to store the metadata storage tree and selecting the second memory device to store the slice storage tree. An initial metadata storage tree structure is generated in the first memory and an initial slice storage tree structure is generated in the second memory. In various embodiments, generating the tree utilization parameters further includes selecting a first plurality of memory devices to store a plurality of metadata storage trees and selecting a second plurality of memory devices to store a plurality of slice storage trees. In various embodiments, the first memory device is selected from the first plurality of memory devices to store the extracted metadata and the second memory device is selected from the second plurality of memory devices to store the received data slice based on the tree utilization parameters.

In various embodiments, a tree utilization threshold is compared to a metadata tree utilization level associated with the metadata storage tree and/or a slice tree utilization level associated with the slice storage tree. The tree utilization parameters are updated by selecting a third memory device to store a third storage tree when tree utilization threshold compares unfavorably to the metadata tree utilization level and/or the slice tree utilization level. In various embodiments, the third memory device includes a highest performing memory type, and the third memory device is selected based on the highest performing memory type.

In various embodiments, a non-transitory computer readable storage medium includes at least one memory section that stores operational instructions that, when executed by a processing system of a dispersed storage network (DSN) that includes a processor and a memory, causes the processing system to receive a slice write request via a network that includes a data slice and extract metadata from the data slice. The metadata is stored in a metadata storage tree in a first memory device of the DST execution unit and the data slice is stored in a slice storage tree in a second memory device of the DST execution unit based on tree utilization parameters.

FIG. 13 a flowchart illustrating an example of utilizing a metadata storage tree. In particular, a method is presented for use in association with one or more functions and features described in conjunction with some or all of FIGS. 1-12 for execution by a dispersed storage and task (DST) execution unit that includes a processor or via another one or more processing systems of a dispersed storage network and/or other storage system that includes at least one processor and memory that stores instruction that configure the processor or processors to perform the steps described below.

Step 1090 includes receiving data for storage. The data can correspond to one or more data objects or other data. Step 1092 includes error encoding the data to produce a plurality of data slices. Step 1094 includes determining metadata for a data slice of the plurality of data slices. Step 1096 includes storing the metadata in a metadata storage tree, where the metadata storage tree is stored via a first plurality of memory devices of a first memory type. Step 1098 includes storing the data slice in a slice storage location, indicated by the metadata, in a second plurality of memory devices of a second memory type, where the first memory type has a higher performance level than the second memory type based on a utilization approach.

In various examples, other metadata can be determined for other data slices of the plurality of data slices, where this other metadata is stored in the same or different metadata storage tree. In various examples, the other data slices of the plurality of data slices can be stored in the same or different memory devices of the second memory type.

In various examples, the utilization approach indicates metadata be stored higher performing memory than data slices. In various examples, the first plurality of memory devices corresponds to a plurality of solid-state memory devices.

In various examples, the method further includes determining at least one first memory device from the first plurality of memory devices to store the metadata based on the utilization approach. In various examples, at least one second memory device is determined from the second plurality of memory devices to store the data slice based on the utilization approach.

In various examples, the method further includes generating utilization parameters for the utilization approach by selecting the first plurality of memory devices to store the metadata storage tree and selecting the second plurality of memory devices to store data slices; and/or generating an initial metadata storage tree structure in at least one of the first memory of memory devices.

In various examples, the method further includes comparing a utilization threshold level to a metadata tree utilization level associated with the metadata storage tree; and/or expanding the metadata tree to accommodate further storage capability based on the metadata tree utilization level comparing unfavorably to the utilization threshold level.

In various examples, the metadata stored in the metadata storage tree includes an address indicating the slice storage location of the data slice in the second plurality of memory devices. In various examples, the first plurality of memory devices store a plurality of metadata storage trees that includes the metadata storage tree. In various examples, the metadata further indicates at least one of: a data object name, or a revision number.

In various embodiments, a non-transitory computer readable storage medium includes at least one memory section that stores operational instructions that, when executed by at least one processing system that includes a processor and a memory, causes the at least one processing system to perform some or all of the steps of FIG. 13 , for example, in conjunction with implementing one or more of the various examples listed above.

In various embodiments, a processing system of a storage system includes at least one processor and a memory storing operational instructions. The operational instructions, when executed by the at least one processor, can cause the processing system to perform some or all of the steps of FIG. 13 , for example, in conjunction with implementing one or more of the various examples listed above. The operational instructions, when executed by the at least one processor, can cause the processing system to: receive data for storage; encode the data via erasure coding to produce a plurality of data slices; determine metadata for a data slice of the plurality of data slices; store the metadata in a metadata storage tree, where the metadata storage tree is stored via a first plurality of memory devices of a first memory type; and/or store the data slice in a slice storage location, indicated by the metadata, in a second plurality of memory devices of a second memory type, where the first memory type has a higher performance level than the second memory type based on a utilization approach.

It is noted that terminologies as may be used herein such as bit stream, stream, signal sequence, etc. (or their equivalents) have been used interchangeably to describe digital information whose content corresponds to any of a number of desired types (e.g., data, video, speech, text, graphics, audio, etc. any of which may generally be referred to as ‘data’).

As may be used herein, the terms “substantially” and “approximately” provides an industry-accepted tolerance for its corresponding term and/or relativity between items. For some industries, an industry-accepted tolerance is less than one percent and, for other industries, the industry-accepted tolerance is 10 percent or more. Other examples of industry-accepted tolerance range from less than one percent to fifty percent. Industry-accepted tolerances correspond to, but are not limited to, component values, integrated circuit process variations, temperature variations, rise and fall times, thermal noise, dimensions, signaling errors, dropped packets, temperatures, pressures, material compositions, and/or performance metrics. Within an industry, tolerance variances of accepted tolerances may be more or less than a percentage level (e.g., dimension tolerance of less than +/−1%). Some relativity between items may range from a difference of less than a percentage level to a few percent. Other relativity between items may range from a difference of a few percent to magnitude of differences.

As may also be used herein, the term(s) “configured to”, “operably coupled to”, “coupled to”, and/or “coupling” includes direct coupling between items and/or indirect coupling between items via an intervening item (e.g., an item includes, but is not limited to, a component, an element, a circuit, and/or a module) where, for an example of indirect coupling, the intervening item does not modify the information of a signal but may adjust its current level, voltage level, and/or power level. As may further be used herein, inferred coupling (i.e., where one element is coupled to another element by inference) includes direct and indirect coupling between two items in the same manner as “coupled to”.

As may even further be used herein, the term “configured to”, “operable to”, “coupled to”, or “operably coupled to” indicates that an item includes one or more of power connections, input(s), output(s), etc., to perform, when activated, one or more its corresponding functions and may further include inferred coupling to one or more other items. As may still further be used herein, the term “associated with”, includes direct and/or indirect coupling of separate items and/or one item being embedded within another item.

As may be used herein, the term “compares favorably”, indicates that a comparison between two or more items, signals, etc., indicates an advantageous relationship that would be evident to one skilled in the art in light of the present disclosure, and based, for example, on the nature of the signals/items that are being compared. As may be used herein, the term “compares unfavorably”, indicates that a comparison between two or more items, signals, etc., fails to provide such an advantageous relationship and/or that provides a disadvantageous relationship. Such an item/signal can correspond to one or more numeric values, one or more measurements, one or more counts and/or proportions, one or more types of data, and/or other information with attributes that can be compared to a threshold, to each other and/or to attributes of other information to determine whether a favorable or unfavorable comparison exists. Examples of such an advantageous relationship can include: one item/signal being greater than (or greater than or equal to) a threshold value, one item/signal being less than (or less than or equal to) a threshold value, one item/signal being greater than (or greater than or equal to) another item/signal, one item/signal being less than (or less than or equal to) another item/signal, one item/signal matching another item/signal, one item/signal substantially matching another item/signal within a predefined or industry accepted tolerance such as 1%, 5%, 10% or some other margin, etc. Furthermore, one skilled in the art will recognize that such a comparison between two items/signals can be performed in different ways. For example, when the advantageous relationship is that signal 1 has a greater magnitude than signal 2, a favorable comparison may be achieved when the magnitude of signal 1 is greater than that of signal 2 or when the magnitude of signal 2 is less than that of signal 1. Similarly, one skilled in the art will recognize that the comparison of the inverse or opposite of items/signals and/or other forms of mathematical or logical equivalence can likewise be used in an equivalent fashion. For example, the comparison to determine if a signal X>5 is equivalent to determining if −X<−5, and the comparison to determine if signal A matches signal B can likewise be performed by determining -A matches -B or not(A) matches not(B). As may be discussed herein, the determination that a particular relationship is present (either favorable or unfavorable) can be utilized to automatically trigger a particular action. Unless expressly stated to the contrary, the absence of that particular condition may be assumed to imply that the particular action will not automatically be triggered. In other examples, the determination that a particular relationship is present (either favorable or unfavorable) can be utilized as a basis or consideration to determine whether to perform one or more actions. Note that such a basis or consideration can be considered alone or in combination with one or more other bases or considerations to determine whether to perform the one or more actions. In one example where multiple bases or considerations are used to determine whether to perform one or more actions, the respective bases or considerations are given equal weight in such determination. In another example where multiple bases or considerations are used to determine whether to perform one or more actions, the respective bases or considerations are given unequal weight in such determination.

As may be used herein, one or more claims may include, in a specific form of this generic form, the phrase “at least one of a, b, and c” or of this generic form “at least one of a, b, or c”, with more or less elements than “a”, “b”, and “c”. In either phrasing, the phrases are to be interpreted identically. In particular, “at least one of a, b, and c” is equivalent to “at least one of a, b, or c” and shall mean a, b, and/or c. As an example, it means: “a” only, “b” only, “c” only, “a” and “b”, “a” and “c”, “b” and “c”, and/or “a”, “b”, and “c”.

As may also be used herein, the terms “processing module”, “processing circuit”, “processor”, “processing circuitry”, and/or “processing unit” may be a single processing device or a plurality of processing devices. Such a processing device may be a microprocessor, micro-controller, digital signal processor, microcomputer, central processing unit, field programmable gate array, programmable logic device, state machine, logic circuitry, analog circuitry, digital circuitry, and/or any device that manipulates signals (analog and/or digital) based on hard coding of the circuitry and/or operational instructions. The processing module, module, processing circuit, processing circuitry, and/or processing unit may be, or further include, memory and/or an integrated memory element, which may be a single memory device, a plurality of memory devices, and/or embedded circuitry of another processing module, module, processing circuit, processing circuitry, and/or processing unit. Such a memory device may be a read-only memory, random access memory, volatile memory, non-volatile memory, static memory, dynamic memory, flash memory, cache memory, and/or any device that stores digital information. Note that if the processing module, module, processing circuit, processing circuitry, and/or processing unit includes more than one processing device, the processing devices may be centrally located (e.g., directly coupled together via a wired and/or wireless bus structure) or may be distributedly located (e.g., cloud computing via indirect coupling via a local area network and/or a wide area network). Further note that if the processing module, module, processing circuit, processing circuitry and/or processing unit implements one or more of its functions via a state machine, analog circuitry, digital circuitry, and/or logic circuitry, the memory and/or memory element storing the corresponding operational instructions may be embedded within, or external to, the circuitry comprising the state machine, analog circuitry, digital circuitry, and/or logic circuitry. Still further note that, the memory element may store, and the processing module, module, processing circuit, processing circuitry and/or processing unit executes, hard coded and/or operational instructions corresponding to at least some of the steps and/or functions illustrated in one or more of the Figures. Such a memory device or memory element can be included in an article of manufacture.

One or more embodiments have been described above with the aid of method steps illustrating the performance of specified functions and relationships thereof. The boundaries and sequence of these functional building blocks and method steps have been arbitrarily defined herein for convenience of description. Alternate boundaries and sequences can be defined so long as the specified functions and relationships are appropriately performed. Any such alternate boundaries or sequences are thus within the scope and spirit of the claims. Further, the boundaries of these functional building blocks have been arbitrarily defined for convenience of description. Alternate boundaries could be defined as long as the certain significant functions are appropriately performed. Similarly, flow diagram blocks may also have been arbitrarily defined herein to illustrate certain significant functionality.

To the extent used, the flow diagram block boundaries and sequence could have been defined otherwise and still perform the certain significant functionality. Such alternate definitions of both functional building blocks and flow diagram blocks and sequences are thus within the scope and spirit of the claims. One of average skill in the art will also recognize that the functional building blocks, and other illustrative blocks, modules and components herein, can be implemented as illustrated or by discrete components, application specific integrated circuits, processors executing appropriate software and the like or any combination thereof.

In addition, a flow diagram may include a “start” and/or “continue” indication. The “start” and “continue” indications reflect that the steps presented can optionally be incorporated in or otherwise used in conjunction with one or more other routines. In addition, a flow diagram may include an “end” and/or “continue” indication. The “end” and/or “continue” indications reflect that the steps presented can end as described and shown or optionally be incorporated in or otherwise used in conjunction with one or more other routines. In this context, “start” indicates the beginning of the first step presented and may be preceded by other activities not specifically shown. Further, the “continue” indication reflects that the steps presented may be performed multiple times and/or may be succeeded by other activities not specifically shown. Further, while a flow diagram indicates a particular ordering of steps, other orderings are likewise possible provided that the principles of causality are maintained.

The one or more embodiments are used herein to illustrate one or more aspects, one or more features, one or more concepts, and/or one or more examples. A physical embodiment of an apparatus, an article of manufacture, a machine, and/or of a process may include one or more of the aspects, features, concepts, examples, etc. described with reference to one or more of the embodiments discussed herein. Further, from figure to figure, the embodiments may incorporate the same or similarly named functions, steps, modules, etc. that may use the same or different reference numbers and, as such, the functions, steps, modules, etc. may be the same or similar functions, steps, modules, etc. or different ones.

Unless specifically stated to the contra, signals to, from, and/or between elements in a figure of any of the figures presented herein may be analog or digital, continuous time or discrete time, and single-ended or differential. For instance, if a signal path is shown as a single-ended path, it also represents a differential signal path. Similarly, if a signal path is shown as a differential path, it also represents a single-ended signal path. While one or more particular architectures are described herein, other architectures can likewise be implemented that use one or more data buses not expressly shown, direct connectivity between elements, and/or indirect coupling between other elements as recognized by one of average skill in the art.

The term “module” is used in the description of one or more of the embodiments. A module implements one or more functions via a device such as a processor or other processing device or other hardware that may include or operate in association with a memory that stores operational instructions. A module may operate independently and/or in conjunction with software and/or firmware. As also used herein, a module may contain one or more sub-modules, each of which may be one or more modules.

As may further be used herein, a computer readable memory includes one or more memory elements. A memory element may be a separate memory device, multiple memory devices, or a set of memory locations within a memory device. Such a memory device may be a read-only memory, random access memory, volatile memory, non-volatile memory, static memory, dynamic memory, flash memory, cache memory, a quantum register or other quantum memory and/or any other device that stores data in a non-transitory manner. Furthermore, the memory device may be in a form of a solid-state memory, a hard drive memory or other disk storage, cloud memory, thumb drive, server memory, computing device memory, and/or other non-transitory medium for storing data. The storage of data includes temporary storage (i.e., data is lost when power is removed from the memory element) and/or persistent storage (i.e., data is retained when power is removed from the memory element). As used herein, a transitory medium shall mean one or more of: (a) a wired or wireless medium for the transportation of data as a signal from one computing device to another computing device for temporary storage or persistent storage; (b) a wired or wireless medium for the transportation of data as a signal within a computing device from one element of the computing device to another element of the computing device for temporary storage or persistent storage; (c) a wired or wireless medium for the transportation of data as a signal from one computing device to another computing device for processing the data by the other computing device; and (d) a wired or wireless medium for the transportation of data as a signal within a computing device from one element of the computing device to another element of the computing device for processing the data by the other element of the computing device. As may be used herein, a non-transitory computer readable memory is substantially equivalent to a computer readable memory. A non-transitory computer readable memory can also be referred to as a non-transitory computer readable storage medium.

One or more functions associated with the methods and/or processes described herein can be implemented via a processing module that operates via the non-human “artificial” intelligence (AI) of a machine. Examples of such AI include machines that operate via anomaly detection techniques, decision trees, association rules, expert systems and other knowledge-based systems, computer vision models, artificial neural networks, convolutional neural networks, support vector machines (SVMs), Bayesian networks, genetic algorithms, feature learning, sparse dictionary learning, preference learning, deep learning and other machine learning techniques that are trained using training data via unsupervised, semi-supervised, supervised and/or reinforcement learning, and/or other AI. The human mind is not equipped to perform such AI techniques, not only due to the complexity of these techniques, but also due to the fact that artificial intelligence, by its very definition—requires “artificial” intelligence—i.e. machine/non-human intelligence.

One or more functions associated with the methods and/or processes described herein can be implemented as a large-scale system that is operable to receive, transmit and/or process data on a large-scale. As used herein, a large-scale refers to a large number of data, such as one or more kilobytes, megabytes, gigabytes, terabytes or more of data that are received, transmitted and/or processed. Such receiving, transmitting and/or processing of data cannot practically be performed by the human mind on a large-scale within a reasonable period of time, such as within a second, a millisecond, microsecond, a real-time basis or other high speed required by the machines that generate the data, receive the data, convey the data, store the data and/or use the data.

One or more functions associated with the methods and/or processes described herein can require data to be manipulated in different ways within overlapping time spans. The human mind is not equipped to perform such different data manipulations independently, contemporaneously, in parallel, and/or on a coordinated basis within a reasonable period of time, such as within a second, a millisecond, microsecond, a real-time basis or other high speed required by the machines that generate the data, receive the data, convey the data, store the data and/or use the data.

One or more functions associated with the methods and/or processes described herein can be implemented in a system that is operable to electronically receive digital data via a wired or wireless communication network and/or to electronically transmit digital data via a wired or wireless communication network. Such receiving and transmitting cannot practically be performed by the human mind because the human mind is not equipped to electronically transmit or receive digital data, let alone to transmit and receive digital data via a wired or wireless communication network.

One or more functions associated with the methods and/or processes described herein can be implemented in a system that is operable to electronically store digital data in a memory device. Such storage cannot practically be performed by the human mind because the human mind is not equipped to electronically store digital data.

One or more functions associated with the methods and/or processes described herein may operate to cause an action by a processing module directly in response to a triggering event—without any intervening human interaction between the triggering event and the action. Any such actions may be identified as being performed “automatically”, “automatically based on” and/or “automatically in response to” such a triggering event. Furthermore, any such actions identified in such a fashion specifically preclude the operation of human activity with respect to these actions—even if the triggering event itself may be causally connected to a human activity of some kind.

While particular combinations of various functions and features of the one or more embodiments have been expressly described herein, other combinations of these features and functions are likewise possible. The present disclosure is not limited by the particular examples disclosed herein and expressly incorporates these other combinations. 

What is claimed is:
 1. A method comprises: error encoding data to produce a plurality of data slices; determining metadata for a data slice of the plurality of data slices; storing the metadata in a metadata storage tree, wherein the metadata storage tree is stored via a first plurality of memory devices of a first memory type; storing the data slice in a slice storage location, indicated by the metadata, within a second plurality of memory devices of a second memory type; determining to access the data slice based on a request; based on determining to access the data slice: accessing the metadata for the data slice in the metadata storage tree to determine the slice storage location for the data slice; and accessing the data slice in the slice storage location based on determining the slice storage location for the data slice via accessing the metadata storage tree.
 2. The method of claim 1, wherein the first plurality of memory devices corresponds to a plurality of solid-state memory devices.
 3. The method of claim 1, wherein the data is encoded via erasure encoding.
 4. The method of claim 1, wherein the data is error encoded via an encoding process to produce the plurality of data slices in accordance with a width parameter of the encoding process.
 5. The method of claim 4, wherein a corresponding decoding process can accommodate a number of failures equal to the width parameter minus an error coding parameter of the encoding process.
 6. The method of claim 1, further comprising: generating an initial metadata storage tree structure in at least one of the first plurality of memory devices.
 7. The method of claim 1, wherein the metadata stored in the metadata storage tree includes an address indicating the slice storage location of the data slice in the second plurality of memory devices.
 8. The method of claim 1, wherein the metadata further indicates a data object identifier.
 9. The method of claim 8, wherein the metadata further indicates a revision number.
 10. The method of claim 1, further comprising: receiving access information from a plurality of storage units that include at least one of: at least one of the first plurality of memory devices, or at least one of the second plurality of memory devices.
 11. The method of claim 10, further comprising: configuring the plurality of storage units based on receiving the access information.
 12. The method of claim 1, further comprising: expanding the metadata storage tree to accommodate further storage.
 13. The method of claim 1, wherein the data is error encoded based on receiving the data for storage.
 14. The method of claim 1, wherein the first memory type has a different performance level from the second memory type.
 15. The method of claim 14, wherein the first memory type has a higher performance level than the second memory type.
 16. A processing system of a storage system comprises: at least one processor; a memory that stores operational instructions that, when executed by the at least one processor, cause the processing system to: error encode data to produce a plurality of data slices; determine metadata for a data slice of the plurality of data slices; store the metadata in a metadata storage tree, wherein the metadata storage tree is stored via a first plurality of memory devices of a first memory type; store the data slice in a slice storage location, indicated by the metadata, within a second plurality of memory devices of a second memory type; determine to access the data slice based on a request; based on determining to access the data slice: access the metadata for the data slice in the metadata storage tree to determine the slice storage location for the data slice; and access the data slice in the slice storage location based on determining the slice storage location for the data slice via accessing the metadata storage tree.
 17. The processing system of claim 16, wherein the first plurality of memory devices corresponds to a plurality of solid-state memory devices.
 18. The processing system of claim 16, wherein the data is encoded via erasure encoding.
 19. The processing system of claim 16, wherein the data is error encoded via an encoding process to produce the plurality of data slices in accordance with a width parameter of the encoding process.
 20. A non-transitory computer readable storage medium comprises: at least one memory section that stores operational instructions that, when executed by a processing system that includes a processor and a memory, causes the processing system to: error encode data to produce a plurality of data slices; determine metadata for a data slice of the plurality of data slices; store the metadata in a metadata storage tree, wherein the metadata storage tree is stored via a first plurality of memory devices of a first memory type; store the data slice in a slice storage location, indicated by the metadata, within a second plurality of memory devices of a second memory type; determine to access the data slice based on a request; based on determining to access the data slice: access the metadata for the data slice in the metadata storage tree to determine the slice storage location for the data slice; and access the data slice in the slice storage location based on determining the slice storage location for the data slice via accessing the metadata storage tree. 